Add color conversion utility and editable palette display functionality; implement color picker and context menu options for palette colors in the GUI.

src/app/gui/color.cc

@@ -16,6 +16,10 @@ ImVec4 ConvertSnesColorToImVec4(const gfx::SnesColor& color) {
   );
 }
 
+gfx::SnesColor ConvertImVec4ToSnesColor(const ImVec4& color) {
+  return gfx::SnesColor(color.x, color.y, color.z);
+}
+
 IMGUI_API bool SnesColorButton(absl::string_view id, gfx::SnesColor& color,
                                ImGuiColorEditFlags flags,
                                const ImVec2& size_arg) {
@@ -58,7 +62,7 @@ absl::Status DisplayPalette(gfx::SnesPalette& palette, bool loaded) {
   static ImVec4 saved_palette[32] = {};
   if (loaded && !init) {
     for (int n = 0; n < palette.size(); n++) {
-      ASSIGN_OR_RETURN(auto color, palette.GetColor(n));
+      auto color = palette[n];
       saved_palette[n].x = color.rgb().x / 255;
       saved_palette[n].y = color.rgb().y / 255;
       saved_palette[n].z = color.rgb().z / 255;
@@ -163,5 +167,102 @@ void SelectablePalettePipeline(uint64_t& palette_id, bool& refresh_graphics,
   ImGui::EndChild();
 }
 
+absl::Status DisplayEditablePalette(gfx::SnesPalette& palette,
+                                    const std::string& title,
+                                    bool show_color_picker, int colors_per_row,
+                                    ImGuiColorEditFlags flags) {
+  // Default flags if none provided
+  if (flags == 0) {
+    flags = ImGuiColorEditFlags_NoAlpha | ImGuiColorEditFlags_NoPicker |
+            ImGuiColorEditFlags_NoTooltip;
+  }
+
+  // Display title if provided
+  if (!title.empty()) {
+    ImGui::Text("%s", title.c_str());
+  }
+  static int selected_color = 0;
+
+  if (show_color_picker) {
+    ImGui::Separator();
+    static ImVec4 current_color = ImVec4(0, 0, 0, 1.0f);
+
+    if (ImGui::ColorPicker4("Color Picker", (float*)&current_color,
+                            ImGuiColorEditFlags_NoSidePreview |
+                                ImGuiColorEditFlags_NoSmallPreview)) {
+      // Convert the selected color to SNES format and add it to the palette
+      gfx::SnesColor snes_color(current_color);
+      palette.UpdateColor(selected_color, snes_color);
+    }
+  }
+
+  // Display the palette colors in a grid
+  ImGui::BeginGroup();  // Lock X position
+  for (int n = 0; n < palette.size(); n++) {
+    ImGui::PushID(n);
+    if ((n % colors_per_row) != 0) {
+      ImGui::SameLine(0.0f, ImGui::GetStyle().ItemSpacing.y);
+    }
+
+    // Create a unique ID for this color button
+    std::string button_id = "##palette_" + std::to_string(n);
+
+    // Display the color button
+    if (SnesColorButton(button_id, palette[n], flags, ImVec2(20, 20))) {
+      // Color was clicked, could be used to select this color
+      selected_color = n;
+    }
+
+    if (ImGui::BeginPopupContextItem()) {
+      if (ImGui::MenuItem("Edit Color")) {
+        // Open color picker for this color
+        ImGui::OpenPopup(("Edit Color##" + std::to_string(n)).c_str());
+      }
+
+      if (ImGui::MenuItem("Copy as SNES Value")) {
+        std::string clipboard = absl::StrFormat("$%04X", palette[n].snes());
+        ImGui::SetClipboardText(clipboard.c_str());
+      }
+
+      if (ImGui::MenuItem("Copy as RGB")) {
+        auto rgb = palette[n].rgb();
+        std::string clipboard =
+            absl::StrFormat("(%d,%d,%d)", (int)(rgb.x * 255),
+                            (int)(rgb.y * 255), (int)(rgb.z * 255));
+        ImGui::SetClipboardText(clipboard.c_str());
+      }
+
+      if (ImGui::MenuItem("Copy as Hex")) {
+        auto rgb = palette[n].rgb();
+        std::string clipboard =
+            absl::StrFormat("#%02X%02X%02X", (int)(rgb.x * 255),
+                            (int)(rgb.y * 255), (int)(rgb.z * 255));
+        ImGui::SetClipboardText(clipboard.c_str());
+      }
+
+      ImGui::EndPopup();
+    }
+
+    // Color picker popup
+    if (ImGui::BeginPopup(("Edit Color##" + std::to_string(n)).c_str())) {
+      ImGuiColorEditFlags picker_flags = ImGuiColorEditFlags_NoSidePreview |
+                                         ImGuiColorEditFlags_NoSmallPreview;
+
+      ImVec4 color = ConvertSnesColorToImVec4(palette[n]);
+      if (ImGui::ColorPicker4("##picker", (float*)&color, picker_flags)) {
+        // Update the SNES color when the picker changes
+        palette[n] = ConvertImVec4ToSnesColor(color);
+      }
+
+      ImGui::EndPopup();
+    }
+
+    ImGui::PopID();
+  }
+  ImGui::EndGroup();
+
+  return absl::OkStatus();
+}
+
 }  // namespace gui
 }  // namespace yaze